You do have to share anything that can impact a life together. Everything comes out eventually, and the betrayal of not knowing in advance can be very destructive.
But you should not share every stupid mistake you made as a teenager. Don’t talk about past relationships, unless there is an aspect that is important for the other to know. (If you are not sure if you should share, speak to a mashpia or coach for insight if and how to share.)
Pratice the W.A.I.T. principle. W.A.I.T. stands for Why Am I Talking? What is the purpose of what it is that you are sharing? You might think that sharing that kind of personal stuff shows your vulnerbaility and trust. Oftentimes, oversharing can make the other person uncomfortable to hear your stuff.